Tire rim



Oct. 17, 1967 P. LEMMERZ 3,347,302

TIRE RIM Filed Aug. 4, 1965 34 43 20 ff/ 2/ 3s Ff' Q13 FJ g. 4 7// 4 25 24 /7 f/ 20 /9 /J l 8 22 INVENTOR.

L? 2 Paa/ emma/z m. a4/W' ATTORNEYS United States Patent O Claims This invention relates to improvements in tire rims for automotive vehicles and is more particularly concerned with heavy duty pneumatic tire rims and their manufacture.

Because of the heavy load which must be `sustained by the pneumatic tire rims used on `such automotive vehicles as trucks, and the like, relatively heavy crosssectional mass of material must be present in the areas of maximum stress, namely, in and adjacent to the terminal lianges, while the intervening body portion of the rim may be of substantially smaller cross-sectional mass, primarily because it is backed up and reinforced by the wheel disk t-o `which the tire rim is attached. j

One way that the desired mass distribution in such tire rims has been attained has been by rolling ybar stock or billets into the desired cross-sectional profile and then uniting circularly curved lengths of the thus rolled section by welding the ends to provide the completed tire rim annulus. However, this is a costly technique.

A much more economical method of making these heavy duty tire rims is to form flat bar material such as suitable grade of steel, into a ring by joining, as by welding, the ends of suitable length pieces curved into ring form, and then rolling the rim profile in the thus formed endless ring. To conserve material and avoid scrap losses the initial width and section of the bar stock is calculated to afford the proper amount of material through transverse elongation and redistribution of material. This method of making such tire rims has, however, encountered certain problems, among which may be mentioned attainment of proper distribution of worked material, and the avoidance of points of weakness and the danger of breakage existing at the weak points.

It is, therefore, an important object of the present invention to provide a new and improved heavy duty pneumatic tire rim which entirely avoids Iany notching etfect weaknesses in the structure.

Another object of the invention is to provide a new and improved tire rim of the character described which affords savings in material and Weight, while avoiding any structural weaknesses, and can -be produced and sold at low cost.

A further object of the invention is to provide a `new and improved heavy duty pneumatic tire rim structure having a novel cross-sectional configuration or profile and affording an advantageous distribution of material and reinforcement.

Other objects, features and Iadvantages of the present invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawing, in which:

FIGURE l is a fragmentary transverse cross-sectional View through a rolled tire rim showing the same as it appears before it has been subjected to the final rolling step according to the present invention;

FIGURE 2 is a fragmentary transverse cross-sectional view through the same tire rim, inserted between complementary shaping rolls, as at the start of the final rolling operation;

FIGURE 3 is a similar transverse cross-sectional View showing the completion of the rolling operation; and

3,347,302 Patented Oct. 17, 1967 FIGURE 4 is a fragmentary transverse cross-sectional view of the completed tire rim.

On reference to FIGURE 4, a tire rim according to the present invention comprises an annular body 5 of substantial axial width having at one axial side lan integral fixed terminal flange 7 and at the opposite axial side a lock-in ring seat flange 8. These flanges are of substantial transverse cross-sectional thickness, such as on the order of twice as thick as the central portion of the rim body 5, and thus of unit Imass adequate to withstand safely the considerable strains and stresses that must be accommodated in normal service.

On its fixed terminal flange 7, the body 5 joins the terminal iiange 7 through a tapered portion 9 which diminishes gradually in thickness from a transversely rounded juncture 10 of at least `as thick `a section as the terminal iiange itself. Inwardly from the juncture 10 the bead seat portion 9 gradually diminishes in thickness and affords an inwardly sloping oblique tire bead seat 11. At the inner edge of the -bead seat 11, the portion 9 joins the remainder of the rim body 5 on an oblique narrow angular reinforcing offset -bend iiange 12 and which avoids any sharp angles by having smoothly rounded radially inner and outer junctures 13 and 14, respectively, with the portion 9 and smoothly rounded radially inner and outer junctures 15 and 17, respectively, with the intermediate annular portion of the rim body 5 which comprises a substantially transversely straight area affording a shallow inset groove 18.

In order to facilitate easy `assembly of a tire onto the rim, and to afford ample clearance for reception of the lock-in ring after the tire has been assembled, the tip diameter of the lock-in seat flange 8 is sufficiently less than the diameter of the bead seat 11. Receptive of Ia split lock-in ring to provide the remaining bead seat, is a Vradially outwardly opening groove 19 axially inwardly adjacent to the flange 8. This groove is defined at its axially inner side by a radially outwardly and axially inwardly oblique ring seat portion 20 which joins the liange 8 on a smoothly rounded juncture 21, with at least the juncture and the adjacent area of the portion 20` of the substantial thickness of the flange 8 for eflicient strain and stress resistance.

At its inner boundary, the ring seat portion 20 merges with the body 5 on smoothly rounded radially inner and outer juncture surfaces 22 and 23, respectively. Adjacent to these juncture surfaces, the rim body is provided with a radially outwardly projecting annular hollow reinforcing shoulder rib 24 having a crown 25 which slopes obliquely axially and radially inwardly. The material of this ri'b is of substantially the same section or thickness as the intermediate inset groove portion 18 of the rim body 5 and provides atits axially inner and outer sides respective offf setting juncture bend angular reinforcing lianges 27 and 28 which join the body on smoothly rounded radially inner and outer juncture surfaces whereby to afford maximum reinforcing effect and durability. The side flange 27 provides one side of the inset groove 18 of which the opposite side is provided by the flange 12.

It will thus be apparent, that the tire rim affords as a result of its profile maximum strength with minimum material and weight. The various annular reinforcing bends and the complete freedom from notching grooves assure freedom from weakness and great durability.

All of the desirable features and advantages enumerated, and others, are attained with the utmost economy by making the tire rim according to the following method from simple wide liat `bar or band steel strip having an original gauge thickness substantially the same as the finished thickness of the terminal flange 7 and the lock-in flange 8, and of the minimum Iband width which will afford the necessary material in the finished tire rim. Pieces of the proper length of such bar or strip material are easily worked and bent into circular ring form and the ends welded together to provide a continuous band. This band is subjected to rolling and working operations resulting in the cross-sectional configuration of FIGURE l. At this stage the fixed terminal flange '7 is in its substantially finished condition, as is also the lock-in flange 8 at the opposite side. Further, these flanges are, at this stage, at their ultimate axially spaced positions.

Since from the start flanges 7 and 8 remain at substantially the original gau'ge or thickness of the band material, they are formed by bending working of the marginal portions of the band into the respective flange shapes, resulting in an axial width which is substantially less than the desired ultimate width of the tire rim. Such ultimate width is then attained by rolling the rim `bottom or body portion 5 to a reduced thickness and axially elongating the same. In such rolling, the body portion 5 remains in a flat condition with both of its opposite faces substantially parallel.

Since it is desirable to have the side flanges 7 and 8 and the rounded junctures 10 and 21 of the undiminished thickness of the starting band material, it is necessary to confine the rolling of the body 5 to an area which is suitably Substantially spaced from the side flanges and the juncture areas adjacent thereto which must desirably remain of a thicker section than the ultimate thickness which will serve the purpose in the body portion 5 itself. Such rolling elongation may be effected either from the fixed terminal flange side of the partially nished rim or from the lock-in flange side of the partially finished rim.

In the example shown in FIGURE 1, the rolling and elongation of the body portion 5 has been effected from the lock-in flange side toward the xed terminal flange 7. As a result of such rolling an accumulation A of material appears as a ridge at juncture of the body portion 5 with the oblique flange portion 20. At the opposite side, that is, the side toward which the rolling elongation progressed, a ridge-like accumulation of material B appears. Due to the nature of the rolling action, and the severe reduction in the elongation there results a relatively sharp line of demarcation or notch N at juncture of the radially outer face of the body portion 5 with the ridge B, leaving a point 0f weakness. Even though there is not such a pronounced notching effect contiguous to the ridge A, a weakness or potential fracture line is present. A similar delineation as N, resulting in a pronounced and dangerous notching would be present at A, if the rolling elongation of the body 5 were started at the flange 7 side of the rim blank and progressed toward the flange 8 side of the blank.

Elimination of any dangerous notching of the rim body is effected by subjecting the rim blank to a final or finishing rolling operation between complementary shaping rolls 29 and 30. These are profiled to work and reshape the tire rim blank of FIGURE 1 to the finished crosssectional configuration of FIGURE 4, performing all the final working at both sides of the rim simultaneously. At their respectively opposite sides, the shaping rolls 29 and 30 have complementary profile portions which receive therebetween and maintain the shape of the side flanges 7 and 8 of the tire rim blank.

Adjacent to the fixed terminal flange receiving side, the forming face perimeters of the rolls 29 and 30 have respective opposed complementary contours for reworking the ridge B of material and the contiguous portions of the rim blank into the tapered bead seat portion 9. To this end, the forming roll 29 has an annular shaping surface 31, and the roll 30 has an opposed annular shaping surface 32. These surfaces 31 and 32 are convergently relatively oriented axially inwardly from the adjacent side toward respective angular annular opposed complementary shaping surfaces 33 and 34 which cooperate in shaping the offsetting and reinforcing bend flange 12. Inwardly from the offsetting forming surfaces 33 and 34, the rolls 29 and 30 have, respectively, opposed horizontally flat opposed rim body engaging annular surfaces 35 and 37.

At the opposite sides of the rolls, shaping surfaces are provided for reshaping the ridge A and contiguous material yof the blank. To this end, the shaping roll 29 has an annular rib 38 respective in the lock-in groove 19 and the shaping roll 30 has a complementary groove 39 receptive of the curved juncture 21 and portion of the rim blank. On the axially inner side of the forming rib 38 is an oblique forming surface 4f) opposing a complementary oblique forming surface 41 on the roll 30 defining the axial inner side of the groove 39. These forming surfaces 40 and 41 are axially inwardly and radially outwardly convergent for shaping the ring seat flange portion 20, and join on smoothly rounded junctures respective opposed substantially parallel narrow annular forming surfaces 42 and 43, respectively, which shape a narrow portion of the body 5 intervening between the reinforcing rib 24 and the ring seat portion 20. At their inner ends, the forming surfaces 42 and 43 merge onto the rounded contours with, respectively, a shaping groove 44 and a complementary shaping rib 45 designed to form the annular rib 24 in the tire rim.

In the roperation of the shaping rolls 29 and 30 on the tire rim blank, the ridge of material A is worked axially inwardly between the opposed shaping surfaces 40, 41 and 42, 43. Material displaced from the ridge A and in the tapering of the flange portion 20 provides for the annular rib 24 into which such material is shaped .by the opposed shaping groove 44 and rib 45. At the same time, the ridge of material B is displaced and reshaped to provide a tapering elongation of the bead seat portion 9 and the offsetting and reinforcing flange 12, by action of the forming surfaces 31, 32 and 33, 34. As a result of this axially inward working of the material in the ridges A and B of the blank elimination of the dangerous notchings, and particularly the notch N, is effected, entirely smoothly rounded contours are formed in the cross-sectional profile of the tire rim between the side flanges, and effective annular lines of reinforcement are provided. In addition, due to the working of the material from the ridges A and B highly desirable strengthening and hardening of the material in annular areas or zones between the side flanges and the body S and more particularly in the bead seat areas thereof is effected for greatly increasing the durability of the tire rim in the portions which although subjected to the severe stresses and strains in use lmay nevertheless now be of minimum thickness, thus saving material and reducing the dead load or weight of the tire rim, and thus of the wheel and vehicle with which associated.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In a tire rim of a character described,

an annular axially elongated body portion of relatively thin section,

an integral substantially double thickness xed terminal flange along one side of the body portion and joined to the body portion by a tire bead seat portion which tapers from the double thickness at the terminal flange to the thinner section of the body portion at juncture therewith,

a lock-in ring retaining flange of substantially twice the thickness of the body portion located along the remaining side of the body portion and defining with an oblique lock-in ring seat portion a lock-in ring groove with the tip of the retaining flange disposed radially inwardly relative to said bead seat whereby to facilitate mounting of a tire onto the rim,

said lock-in ring seat tapering toward thinner section to juncture with the rim body,

a radially outwardly projecting annular reinforcing hollow rib in said body portion adjacent to said ring seat portion, and

a narrow portion of the body portion intervening between the reinforcing rib and the ring seat portion,

said rib having a crown sloping obliquely radially and axially inwardly.

2. A tire rim as defined in claim 1, in which said reinforcing rib has offsetting angular side reinforcing flanges at both of its sides joining said body portion.

3. In a tire rim of a character described,

an annular axially elongated body portion of relatively thin section,

an integral substantially double thickness fixed terminal flange along one lside of the body portion and joined to the body portion by a tire bead seat portion which tapers `from the double thickness at the terminal flange to the thinner section of the body portion at juncture therewith,

a lock-in ring retaining flange lof substantially twice the thickness of the body portion located along the remaining side of the body portion and defining with an oblique lock-in ring seat portion a lockein ring groove with the tip `of the retaining flange disposed radially inwardly relative to said bead seat whereby to facilitate mounting of a tire onto the rim,

said lock-in ring seat tapering toward thinner section to juncture with the rim body,

a radially outwardly projecting annular reinforcing hollow rib in said body portion adjacent to said ring seat portion and with a narrow portion of the body portion intervening between the reinforcing rib and the ring seat portion,

said rib having a crown sloping obliquely radially and axially inwardly,

said rein-forcing rib having offsetting angular side reinforcing flanges joining said body portion,

and a narrow offsetting angular reinforcing bend flange joining said bead seat portion and body portion and affording a shallow inset groove between said rib and said offsetting bend flange.

4. In a tire rim of the character described,

an annular axially elongated body portion of relatively thin substantially uniform section,

an integral fixed terminal flange along one side of the body portion and joined to the body portion Iby a tire bead seat portion,

a lock-in-ring retaining flange located along the remaining side of the body portion and dening a lock-inring groove having a ring seat portion along its inner side,

said flanges being of substantially greater thickness than said body portion and said ring seat portion tapering smoothly to juncture with the body portion,

a radially outwardly projecting annular reinforcing hollow rib in said body portion adjacent to said ring seat portion having axially oppositely facing sides and with a narrow portion of the body portion intervening between the reinforcing rib and the ring seat portion,

and a narrow insetting angular annular reinforcing bend flange joining said bead seat portion and said body portion and providing one side of a shallow radially outwardly Iopening inset groove of which the confronting side of said rib provides the opposite side of the inset groove.

References Cited UNITED STATES PATENTS 2,152,757 4/1939 Burger. 2,200,361 5/1940 Hunt 301-97 2,537,624 1/1951 Brink 152--410 2,948,568 8/1960 Hykes 301-97 X 3,013,842 12/ 1961 Walther 301-20 FOREIGN PATENTS `611,573 11/1948 Great Britain.

RICHARD I JOHNSON, Primary Examiner. BENJAMIN HERSH, Examiner. 

1. IN A TIRE RIM A CHARACTER DESCRIBED, AN ANNULAR AXIALLY ELONGATED BODY PORTION OF RELATIVELY THIN SECTION, AN INTEGRAL SUBSTANTIALLY DOUBLE THICKNESS FIXED TERMINAL FLANGE ALONG ONE SIDE OF THE BODY PORTION AND JOINED TO THE BODY PORTION BY A TIRE BEAD SEAT PORTION WHICH TAPERS FROM THE DOUBLE THICKNESS AT THE TERMINAL FLANGE TO THE THINNER SECTION OF THE BODY PORTION AT JUNCTURE THEREWITH, A LOCK-IN RING RETAINING FLANGE OF SUBSTANTIALLY TWICE THE THICKNESS OF THE BODY PORTION LOCATED ALONG THE REMAINING SIDE OF THE BODY PORTION AND DEFINING WITH AN BOBLIQUE LOCK-IN RING SEAT PORTION A LOCK-IN RING GROOVE WITH THE TIP OF THE RETAINING FLANGE DISPOSED RADIALLY INWARDLY RELATIVE TO SAID BEAD SET WHEREBY TO FACILITATE MOUNTING OF A TIRE ONTO THE RIM, SAID LOCK-IN RING SEAT TAPERING TOWARD THINNER SECTION TO JUNCTURE WITH THE RIM BODY, A RADIALLY OUTWARDLY PROJECTING ANNULAR REINFORCING HOLLOW RIB IN SAID BODY PORTION ADJACENTY TO SAID RING SEAT PORTION, AND A NARROW PORTION OF THE BODY PORTION INTERVENTING BETWEEN THE REINFORCING RIB AND THE RING SEAT PORTION, SAID RIB HAVING A CROWN SLOPING OBLIQUENTLY RADIALLY AND AXIALLY INWARDLY. 